driver: Fix a version number check to work around a bug in the zsh version whereunder the check should return false.

The bug is as follows:

    % zsh-5.8 -fc 'autoload is-at-least; is-at-least 5.8.0.2 && echo yes || echo no'
    yes
    % zsh-5.8 -fc 'autoload is-at-least; is-at-least 5.8.0.2 $ZSH_VERSION && echo yes || echo no'
    yes

This commit deploys the following workaround:

    % zsh-5.8 -fc 'autoload is-at-least; is-at-least 5.8.0.2 $ZSH_VERSION.0.0 && echo yes || echo no'
    no

Fixes #756.

Author: danielshahaf

zsh-syntax-highlighting.zsh

@@ -163,7 +163,7 @@ _zsh_highlight()
         # On zsh version 5.8.0.2 between the aforementioned commit and the
         # first Config/version.mk bump after it (which, at the time of writing,
         # is yet to come), this condition will false negative.
-        if is-at-least 5.8.0.3; then
+        if is-at-least 5.8.0.3 $ZSH_VERSION.0.0; then
           integer -gr zsh_highlight__memo_feature=1
         else
           integer -gr zsh_highlight__memo_feature=0
@@ -414,7 +414,7 @@ _zsh_highlight_call_widget()
 #
 #    See _zsh_highlight for the magic version number.  (The use of 5.8.0.2
 #    rather than 5.8.0.3 as in the _zsh_highlight is deliberate.)
-if is-at-least 5.8.0.2 && _zsh_highlight__function_callable_p add-zle-hook-widget
+if is-at-least 5.8.0.2 $ZSH_VERSION.0.0 && _zsh_highlight__function_callable_p add-zle-hook-widget
 then
   autoload -U add-zle-hook-widget
   _zsh_highlight__zle-line-finish() {